This document defines the STAC Server (Static / File-Based) sub-system, part of the Debrief Rewrite under the Core Sub-Systems category.

Purpose

The static STAC Server provides local access to spatial/temporal datasets (primarily GeoJSON FeatureCollections), along with metadata describing background layers and serial metadata. It enables basic file-based deployments of Debrief with no REST services or server processes.

Implementation Strategy

• Follows STAC Specification using static catalog layout
• Implements a Year > Exercise > Serial folder hierarchy
• Each serial is represented as a single GeoJSON file + STAC item.json
• catalog.json and collections/*.json form the root metadata index
• Background tile metadata is included if needed per serial

Folder Structure

stac-root/
├── catalog.json
├── collections/
│   └── tracks.json
├── 2026/
│   └── cold-depths/
│       └── serial-01/
│           ├── item.json
│           └── serial-01.geojson

STAC Metadata Files

• catalog.json: top-level entry point
• collections/tracks.json: describes the FeatureCollection type
• item.json: metadata for a single serial, references one GeoJSON file as an asset

Example item.json:

{
  "id": "serial-01",
  "type": "Feature",
  "stac_version": "1.0.0",
  "collection": "tracks",
  "properties": {
    "start_datetime": "2026-02-05T09:00:00Z",
    "end_datetime": "2026-02-05T12:00:00Z",
    "exercise": "cold-depths",
    "serial": "S01"
  },
  "assets": {
    "plot": {
      "href": "serial-01.geojson",
      "type": "application/geo+json",
      "title": "GeoJSON plot for serial-01"
    }
  }
}

Maintenance and Control Flow

STAC metadata and folder hierarchy are maintained automatically by the Import Service or a lightweight STAC Indexer.

Events and Updates

• New Wargame:

  • Create Year/Exercise/ folder
  • Update catalog.json with new exercise link

• New Serial:

  • Create Serial/ subfolder under Exercise/
  • Generate serial-XX.geojson and item.json
  • Update catalog.json and relevant collection.json

• Save Serial:

  • Overwrite or update serial-XX.geojson
  • Update item.json (timestamp, bounding box, duration)

• Delete Serial:

  • Delete GeoJSON and item.json
  • Update catalog.json to remove reference

• Delete Wargame:

  • Delete entire Exercise/ folder
  • Update catalog.json to remove wargame link

• Browse Years, Wargames, Serials:

  • UI reads catalog.json and walks directory tree
  • Uses STAC links to populate tree/table views in client UI

Spatial/Temporal Discovery

• Each item.json includes bounding box and time range
• Client can query this metadata to visualise data availability on a map or timeline

Notes

• No server process is required
• All metadata is file-based and portable
• Designed for MOD deployments with static file access
• Can be adapted later to integrate with server-based STAC services

STAC Metadata Events – Sequence Diagrams

📁 New Wargame

📂 New Serial

💾 Save Serial (Update)

🗑️ Delete Serial

🧹 Delete Wargame

🔍 Browse Years / Exercises / Serials